Integrated Utilization Strategy for Soybean Oil Deodorizer Distillate: Synergically Synthesizing Biodiesel and Recovering Bioactive Compounds by a Combined Enzymatic Process and Molecular Distillation

Abstract

Soybean oil deodorizer distillate (SODD) is well recognized as a good source of both biodiesel and high-value bioactive compounds of tocopherols, squalene, and phytosterols. To achieve a one-step synthesis of biodiesel and recovery of bioactive compounds from SODD, four commercial immobilized enzymes (Novozym 435, Lipozyme TLIM, Lipozyme RMIM, and Lipozyme RM) and one self-prepared immobilized lipase MAS1-H108A were compared. The results showed that immobilized lipase MAS1-H108A due to the better methanol tolerance and higher catalytic activity gave the highest biodiesel yield of 97.08% under the optimized conditions: molar ratio of 1:2 (oil/methanol), temperature of 35 °C, and enzyme loading of 35 U/g SODD, even after 10 persistent cycles without significant decrease of activity. Simultaneously, there was no loss of tocopherols and squalene in SODD during the enzymatic reaction. Pure biodiesel (characterized by fourier transform infrared (FT-IR) and nuclear magnetic resonance (NMR)) and a high concentration of bioactive compounds could be successfully separated by molecular distillation at 100 °C. In a word, this work provides an interesting idea to achieve environmentally friendly treatment of SODD by combining an enzymatic process and molecular distillation, and it is suitable for industrial production.

Study of vegetable oils and their blends using infrared reflectance spectroscopy and refractometry

“…However, there were structural and chemical changes in the blend's constituents. The resulting dependence was specified by different IOR for different oils or, conversely, similar index indicators ( Lu et al, 2021 ; Lv et al, 2021 ).…”

Esterification effect on the recovery of vitamin E from palm oil refining residues by molecular distillation

“…Physical properties (density and kinematic viscosity) of the distillate stream were also determined for potential applications. [ 20 ] Density at 40°C (, kg m −3 ) was determined by pycnometry, and the density at 15°C (, kg m −3 ) was calculated using the correlation described in Equation (), [ 38 ] where T (°C) is the temperature of the measurement. Kinematic viscosity at 40°C (, mm 2 s −1 ) was calculated according to Equation (), where (Pa s) is the dynamic viscosity measured at 60 rpm in a rotary viscosimeter (Quimis, Q860A21) coupled with a water jacket to maintain constant temperature during the measurement. …”

“…Esterification of PFAD has been studied for biodiesel production because it is a low‐cost and abundant raw material, [ 19 ] but there is a lack of research that explores the benefits of PFAD esterification in the recovery of vitamin E by molecular distillation. Additionally, Lv et al [ 20 ] showed that the esterification–molecular distillation combined process can be applied both to recover phytonutrients and biodiesel from SODD. However, there is a lack of studies in the scientific literature about the pretreatment of the PFAD by esterification evaluating simultaneously the conversion of the FFA and losses in the vitamin E during this process.…”

Production, Characterization, Delivery, and Cholesterol-Lowering Mechanism of Phytosterols: A Review

“…The esterification-distillation method is generally used to produce phytosterols from deodorized distillates, which is a byproduct of the vegetable oil industry . For example, the deodorized distillates of soybean oil mainly contain phytosterols, phytosterols esters, free fatty acids, glycerides, vitamin E, odorants, and pigments . The deodorized distillates are pretreated by esterification to convert free fatty acids and glycerides into fatty acid methyl esters with lower boiling points.…”

“…Due to their diverse physiological effects, phytosterols have been extensively used in functional foods, supplements, and pharmaceutical products designed to enhance human health . Numerous approaches have been developed to isolate or produce phytosterols, such as organic solvent extraction, supercritical carbon dioxide (CO 2 ) extraction, molecular distillation, and fermentation . There are also many analytical tools that can be used for the qualitative and quantitative analysis of phytosterols, including thin layer chromatography (TLC), gas chromatography (GC), liquid chromatography (LC), and infrared spectroscopy .…”